On the evening of his thirtieth birthday the American poet Delmore Schwartz, who as a young man was consumed by a dream of limitless achievement, wrote in his diary: 'Too late, already too late.' Schwartz, about whom Saul Bellow wrote so well in his novel Humboldt's Gift, eventually declined into alcoholic disappointment. Adam, the narrator of The Body, the 126-page novella that opens this excellent collection of stories, is, like Schwartz, a writer all too aware of his own mortal failure. Indeed, his memoir is titled 'Too Late' and he wanders the London streets in a condition of hopeless belatedness, his every third thought the grave.

Adam is an old man, aware of the decay of his body and of all the bodies around him. He also believes that the body and the soul are not two ways of describing the same thing, namely a human being, but distinct, separate entities. One night, at a party, he is told of a London clinic that is pioneering a new, expensive technique transplanting an individual's brain - and thus his essence - into a younger, fitter body of his choice (of course, this is very bad science, but a good fictional set-up).

This being a Kureishi story, the writer, in his new tanned, muscular body, is blessed with a 'fine, thick penis', which he naturally uses as often as he can with whomever he can. Assuming the identity of an itinerant backpacker, Adam sets off on a tour of Europe, where he goes to clubs and experiments with drugs. He eventually settles, amid a group of bohemian women, on a remote Greek island, as you do. But increasingly he feels a prisoner inside his own body and longs not only to return to his old life with his wife in London, but to his old body as well.

The Body, though utterly preposterous, is written with Kureishi's usual brevity and cool precision. It is also philosophically interesting. The old Cartesian idea of a separation between mind and body is now absolutely discredited. But we remain intensely aware of our own duality, if only metaphorically. The soul may not, as Andrew Marvell wrote, be 'fettered in feet' and 'manacled in hands', but Kureishi's Adam, and no doubt many like him, such as those in America experimenting with cryogenics, clearly believe that the key to personal identity resides not in their physical bodies, but in a certain continuity of consciousness through time.

Elsewhere, in this collection, we encounter familiar Kureishi archetypes and themes: urban ennui, the paradoxical intimacy of cold, emotionless sex, the impossibility of love, the confusion between parents and their children and between husbands and wives. In 'Straight', a man recovering from an accident in which he nearly drowned returns to his old life - the casual sex, the overlit parties in smart West End clubs, the coke-dependent debauchery - with contempt and disappointment. He, like Adam, is undergoing a peculiar metamorphosis, as he seeks to remake himself and escape the taint of the past.

In the best story here, 'The Real Father', a film editor takes his young son on a trip to the English seaside. The man, Mal, and the boy scarcely know each other. They have certainly never lived together - the boy was the result of a brief, casual relationship many years before. Mal tries forlornly to buy his son's affection. They take a room together in a boarding house and, once his son is asleep, Mal wanders down to a beachside bar where he meets some youths gathered around a boom-box.

They offer him some whisky and urge him to dance. It is years since he has danced, and even then he did not dance so much as 'pogo'. Yet as he is drawn towards the music, Mal finds himself beginning to hop and then to pogo, 'alone of course, jumping up towards the sky'. The next morning, he discovers that things are a little easier with his son, as if that moment of heightened self-abandon the previous night has awakened something in him, a subdued sense of fellow feeling and inchoate love for the boy.

It is hard to explain why exactly Hanif Kureishi is such a good writer, because his sentences are often very ordinary. Rather, the effect of reading him is cumulative: you are impressed by a certain intensity, and indeed integrity, of vision. He can be very cold and cruel; but at the same time he understands essential truths about the drift and lassitude of modern life in cities. His is a fiction of wintry interiors, of emotional dislocation and of strangers seeking comfort with one another.

There are moments of humour here (such as in 'Touched', when a young British-Indian boy in a well-rendered 1950s south London suburb allows himself to be molested, in exchange for money, by a local blind woman) of the kind that made his debut, The Buddha of Suburbia, such a lascivious pleasure, but his worldview is bleak and much darker now, though no less appealing.